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Full text of "Alaskan glacier studies of the National Geographic Society in the Yakutat Bay, Prince William Sound and lower Copper River regions"

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GLACIERS OF UNAKWIK INLET AND COLLEGE FIORD         317
that the snowfall (a) at Kenai, 180 miles southwest of College Fiord increased from 32 inches in 1901-1902 to 109 inches in 1902-1903, corresponding to the great increase at Fort Liscum in 1902-1903, and (b) the snowfall at Sunrise, 65 miles southwest of College Fiord, increased from 83 inches in 1906-1907 to 158 inches in 1907-1908, corresponding to the increase at Fort Liscum in the latter year. At Chickaloon, 950 feet above sea level in the Matanuska valley north of the Chugach Mountains and only 45 miles northwest of College Fiord, we have snowfall records during only two winters. These show 95i inches in 1907-1908 (October 25 to March 31) and only 75$ inches during the corresponding months of 1910-1911. At Copper Center, 90 miles northeast of College Fiord, the increased snowfall appears for 1907-1908, but there was not as much in 1902-1903 as in the following year, and the greatest snowfall was in 1905-1906. Ten out of fifteen other stations in distant parts of Alaska, however, show a great increase of snowfall in 1902-1903 and 1907-1908.
Secondly, the two glaciers extending down to sea level close to Fort Liscum show no adequate response to the increase in snowfall in 1907-1908. Valdez Glacier is only 8 miles north and Shoup Glacier only 10 miles northwest of Fort Liscum. Following the doubling of snowfall in 1902-1903, however, the Valdez Glacier had a slight advance between 1905 and 1908; but the adjacent Shoup Glacier had no such advance, and Valdez Glacier moved forward only 250 to 300 feet and then commenced to recede again, as it has done ever since and as we know from annual observations that it has been doing ever since 1898. Columbia Glacier, midway between College Fiord and Fort Liscum, began to advance in 1908 and continued slow forward motion at least until 1911.
All this suggests that the tremendous annual snowfall of 187 to 671 inches (15$ to 56 feet) at Fort Liscum, and the smaller amounts at Sunrise, Kenai, and Copper Center, may not be representative of the snowfall in the nev6 fields of the adjacent glaciers, where the precipitation is probably even greater, but does not necessarily fluctuate in exactly the same way.
On these accounts, though it is probably, it is not absolutely safe to ascribe the forward movement of the Meares Glacier in Unakwik Inlet and the eight glaciers in College Fiord in 1910 to the increased precipitation recorded at Fort Liscum during the winters of 1902-1903 or 1907-1908. The temperature records are open to the same limitations.
The only satisfactory attitude to take at present is to ascribe this great renewal of activity of certain of these glaciers either (a) to climatic variations or (b) to earthquake avalanching, and then wait to see whether other adjacent glaciers, now retreating, such as the Amherst in College Fiord and the Barry in Harriman Fiord, also advance, and whether those now advancing continue to advance for several years as the Columbia Glacier has done, suggesting a climatic explanation, or whether they develop the characteristics of the earthquake-stimulated Yakutat Bay glaciers, having spasmodic advances which are of short duration. It would be most desirable if some one could revisit the Unakwik Inlet and College Fiord glaciers in a year or two to gather information on this important question.
The initiation of what seems to be a general advance of the glaciers of western Prince William Sound is a matter of no little importance. Fourteen ice tongues began to advance in 1909-1910—eight of them in College Fiord—and a fifteenth had commenced to move forward in 1908. The importance lies (a) in distinguishing whether this advance is climatic or due to earthquake avalanching; (b) in determining whether the advance is